Electrification in Martian dust devils: Possibility and implications

During summer in Mars' southern hemisphere, dust devils/storms routinely sweep across the surface, lofting massive quantities of dust that drastically lower the atmosphere's electrical conductivity. In this study, we investigate a dust devil triggered under either low-dust or high-dust conditions, which is set by a prior dust activity, and show outcomes of its electrification by varying atmospheric conductivity in existing models. By tracking how the electric field evolves and comparing it to Mars' breakdown threshold, we determined a narrow range of conductivity from [1–9.6] × 10⁻¹³ S/m, as the condition where near surface lightning becomes feasible. We also examined conductivity profiles spanning few Martian years, confirming that these low-conductivity conditions indeed recur on Mars. By analyzing time-domain evolution of electric field in Martian dust devils, we derived the discharge current characteristics based on allowable streamer speeds on Mars. The current provided the three moments in the three-component analysis, viz. current moment, charge moment and radiation moment, to estimate electromagnetic radiation's frequency spectrum. The electrical discharge launches extremely low frequency waves in surface-ionosphere cavity, potentially exciting Schumann Resonances on Mars. We further compute the resonator's quality factor and signal attenuation under different dust conditions. Our findings highlight that dust-driven electrical discharges on Mars could be strong enough to generate detectable Extremely Low Frequency signals. The work could be useful to plan observations of lightning or Schumann Resonance, the most promising detection related to electrical activity on the Red Planet, by a future mission.